From 6110ddc8b1d11d3fce93d5b6de7dc073f9410775 Mon Sep 17 00:00:00 2001
From: Dennis Mannhart <dennis@yuneecresearch.com>
Date: Tue, 27 Nov 2018 14:08:16 +0100
Subject: [PATCH] math Functions constrain X_in of exponentialFromLimits
 function

---
 src/lib/mathlib/math/Functions.hpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/lib/mathlib/math/Functions.hpp b/src/lib/mathlib/math/Functions.hpp
index 481df20f68..1a6016d2a2 100644
--- a/src/lib/mathlib/math/Functions.hpp
+++ b/src/lib/mathlib/math/Functions.hpp
@@ -173,9 +173,11 @@ const T gradual(const T &value, const T &x_low, const T &x_high, const T &y_low,
  * @param Y_max maximum output at X = 0
  */
 template<typename T>
-const T expontialFromLimits(const T &X, const T &Y_min, const T &Y_mid, const T &Y_max)
+const T expontialFromLimits(const T &X_in, const T &Y_min, const T &Y_mid, const T &Y_max)
 {
 	T SIGMA_NORM = (T)0.001;
+	// constrain X_in to the range of 0 and 2
+	T X = math::constrain(X_in, (T)0, (T)2);
 	// If Y_mid is exactly in the middle, then just apply linear approach.
 	bool use_linear_approach = false;